urinary neutrophil gelatinase–associated lipocalin (uNGAL) strongly predicts short–term inpatient mortality in both unadjusted and adjusted models. Patients with hepatorenal syndrome (HRS) may have uNGAL levels intermediate between those with prerenal azotemia and intrinsic acute kidney injury (iAKI). Further studies are needed to determine if uNGAL can improve discrimination of HRS from other types of acute kidney injury and predict short– and long–term cirrhosis outcomes.